1. Field of the Invention
The present invention relates to an apparatus for injection-molding a resin frame such as a resin molding, gasket, or seal around a peripheral edge of a glass sheet.
2. Description of the Prior Art
Resin frames are injection-molded as seals or gaskets around peripheral edges of glass sheets such as automobile front windshields. Conventional apparatus for injection-molding such resin frames are disclosed in Japanese laid-open utility model publications Nos. 56-171213 and 2-50318 and Japanese patent publications Nos. 4-7978 and 47982.
FIG. 4 of the accompanying drawings schematically shows one such conventional injection-molding apparatus which is disclosed typically in the latter two publications. As shown in FIG. 4, the conventional injection-molding apparatus has a pair of upper and lower molds 101, 102 for placing a glass sheet G therein, the upper and lower molds 101, 102 having respective seal members 103, 104 such as of an elastomeric resin. In operation, a portion of the glass sheet G which is spaced slightly inwardly from the peripheral edge thereof is gripped by the seal members 103, 104, and a resin material is injected into a mold cavity 105 which is defined around the peripheral edge of the glass sheet G between the upper and lower molds 101, 102 and the seal members 103, 104.
The conventional injection-molding apparatus is disadvantageous in that the seal members 103, 104 deteriorate soon and hence are deformed and become poor in their sealing capability quickly because the resin material is brought into direct contact with the seal members 103, 104 at high temperature and under high pressure.